A mobile device can communicate wirelessly with a wireless communication network by employing radio frequency (RF) field propagation. The radio frequency, a frequency within the electromagnetic spectrum associated with radio wave propagation, is supplied to an antenna that creates an electromagnetic field that propagates through space. An element of a wireless communication network can be a base station, for example, a cell tower of a cellular network, or an access point of a wireless local area network (WLAN) or a wireless personal area network (WPAN). The base station can allow a mobile device to communicate with a wired network through an access gateway. Typically, the base station broadcasts a beacon signal providing key information necessary for mobile devices to connect to it. A base station can serve mobile devices located in a geographic area.
A mobile device can include one or more location-aware applications that are configured to perform location-based functions such as point-of-interest searching and transit routing. A mobile device equipped with a receiver of a global navigation satellite system (GNSS), such as Global Positioning System (GPS), can receive satellite data signals to determine a position estimate within several tens of meters of accuracy. In outdoor environments, a GNSS receiver can be associated with multiple base stations due to the mobile device being within a communication range of various wireless communication networks (e.g., inside a cellular network and a WLAN) at the same time. A mobile device located in a geographic area where GNSS signals may not be available or are weak (e.g., in or near buildings) can sometimes determine its location using the locations of the base stations to which the mobile device can detect and connect, if the locations of the base stations are known. The information about a base station can be easily collected and updated by scanning and detecting, and is independent of GNSS signals. However, the base station locations may not be available to mobile devices with GNSS receivers; even though, it may be available to wireless communication vendors.